Fast clear port

ABSTRACT

Described herein are implantable ports including a housing with a fluid receptacle, a port stem in fluid communication with the fluid receptacle, and a septum covering the fluid receptacle. The ports may be configured to reduce the priming volume by including a plurality of fluid-locked chambers and/or one or more base mats. The ports may also include a hydrophobic coating on one or more surfaces thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e), to U.S.Provisional Application No. 60/635,818, filed Dec. 14, 2004, which isincorporated by reference into this application as if fully set forthherein.

BACKGROUND OF THE INVENTION

A variety of subcutaneously implantable access ports have been utilizedby physicians to deliver fluids to, or withdraw fluids from, thebloodstream or other subcutaneous cavities inside a patient. Suchvascular access ports generally include a needle-impenetrable housingenclosing a fluid reservoir that is sealed by a needle penetrableseptum. The access port also includes a port stem that projects from thehousing and has a fluid passageway that communicates with the fluidreservoir. The port stem can be used to couple a catheter to thehousing.

Typically, an access port may be attached to a catheter (e.g., via theport stem) after the catheter has been inserted within a subject. Theaccess port is then implanted into an appropriate region of thesubject's body so that the distal end of the catheter is disposed at apredetermined location where a therapeutic agent is to be delivered fromthe access port. Once the vascular access port is implanted, a needleattached to a syringe can selectively access the reservoir of the accessport by penetrating the subject's skin overlaying the access port andenter the septum of the access port. The needle and syringe can thendeliver fluids (including fluids containing medication or othertherapeutics) to the target site. The fluids travel through thereservoir, port stem, and catheter, and are released from the distal endof the catheter. Alternatively, a syringe can be used to aspirate andwithdraw bodily fluids from the region near the distal end of thecatheter.

Fluid (e.g., medication) may be dispensed from the fluid reservoir ofthe access port by means of a non-coring needle, inserted through thepenetrable septum. For example, this fluid may be applied from thedistal end of the catheter to an entry point into the venous system ofthe body of the patient. Blood may also be withdrawn (e.g., forsampling) from the body of the patient through an access port byapplying negative pressure in the fluid cavity, drawing blood throughthe catheter, into the fluid cavity, and then out of the body of thepatient through the needle. To prevent clotting, the withdrawal routemay be flushed with a saline solution or heparin using a non-coringneedle injected into the access port in the same manner as if amedication were being infused. Both intermittent and continualinjections of medication may be dispensed by the access port. Continualaccess may involve the use of a non-coring needle attached to anambulatory-type pump or gravity feed bag suspended above the patient.The ambulatory-type pump or the gravity feed bag continually deliversthe medication or fluid through the needle to the fluid cavity in theaccess port and from there through the catheter to the entry point intothe venous system.

Examples of access ports are described in U.S. Pat. No. 4,772,270,titled “INSEPARABLE PORT/CATHETER TUBE ASSEMBLY AND METHODS” issued toWiita et al., dated Sep. 20, 1988; U.S. Pat. No. 4,963,133, titled“CATHETER ATTACHMENT SYSTEM” issued to Whipple, dated Oct. 16, 1990;U.S. Pat. No. 5,045,060, titled “IMPLANTABLE INFUSION DEVICE” issued toMelsky et al., dated Sep. 3, 1991; U.S. Pat. No. 5,129,891, titled“CATHETER ATTACHMENT DEVICE” issued to Young, dated Jul. 14, 1992; U.S.Pat. No. 5,137,529, titled “INJECTION PORT” issued to Watson et al.,dated Aug. 11, 1992; U.S. Pat. No. 5,312,337, titled “CATHETERATTACHMENT DEVICE” issued to Flaherty et al., dated May 17, 1994; U.S.Pat. No. 5,360,407, titled “IMPLANTABLE DUAL ACCESS PORT WITH TACTILERIDGE FOR POSITION SENSING” issued to Leonard, dated Nov. 1, 1994; U.S.Pat. No. 5,399,168, titled “IMPLANTABLE PLURAL FLUID CAVITY PORT” issuedto Wadsworth, Jr. et al., dated Mar. 21, 1995; U.S. Pat. No. 5,833,654,titled “LONGITUDINALLY ALIGNED DUAL RESERVOIR ACCESS PORT” issued toPowers et al., dated Nov. 10, 1998; U.S. Pat. No. 6,113,572, titled“MULTIPLE-TYPE CATHETER CONNECTION SYSTEMS” issued to Gailey et al.,dated Sep. 5, 2000; U.S. Pat. No. 6,213,973, titled “VASCULAR ACCESSPORT WITH ELONGATED SEPTUM” issued to Eliasen et al., dated Apr. 10,2001; and U.S. Pat. No. 6,287,293, titled “METHOD AND APPARATUS FORLOCATING THE INJECTION POINT OF AN IMPLANTED MEDICAL DEVICE” issued toJones et al., dated Sep. 11, 2001, each of which is incorporated hereinby reference in its entirety.

In certain circumstances, it may be desirable to reduce the primingvolume of an access port to enhance the clearance of fluid (includingmedications) from the access port. The “priming volume” of an accessport is defined herein as the volume of fluid contained within the portand port stem (and may include the fluid within an attached catheter).Reducing the priming volume may decrease the amount of fluid required toflush fluid from the access port, also referred to as clearing theaccess port. However, applicants have recognized that there is atradeoff between the size and ease of use of the access catheter and thepriming volume. In particular, an access port must be deep enough forthe needle to penetrate the septum such that the opening in the needletip is within the reservoir to allow fluid to pass into and out of theneedle. Thus, most commonly available access ports are relatively largein size (e.g., have a large housing and fluid reservoir) so that theyare easy to locate and inject into; however, as mentioned, the largesize may contribute to a larger than optimal priming volume therein.

In certain circumstances, applicants have recognized that it can bedesirable to provide access ports with geometries and configurationsthat assist in reducing the priming volume. Such access ports may bereferred to herein as “fast clear ports.” Thus, described herein arefast clear ports, systems including fast clear ports, methods of usingfast clear ports, and methods of manufacturing fast clear ports.

BRIEF SUMMARY OF THE INVENTION

Accordingly, described herein are fast clear ports configured to rapidlyclear fluid. In one embodiment, a fast clear port includes amulti-chamber implantable vascular access port having a housing with adivided fluid receptacle (divided into a plurality of chambers), a portstem in fluid connection with the chambers of the receptacle, and aseptum configured to cover the fluid receptacle. The port stem may beconfigured to couple to a catheter. Multi-chamber access ports may haveany number of chambers and may include a number of configurations. Inone embodiment, a single fluid receptacle may be divided into more thanone chamber into which fluid may be applied or withdrawn by a needleinserted through a port septum. For example, the single fluid receptacleof the access port may be divided up into two, three, or more chambers.Generally, a divided single fluid receptacle is covered by a singleseptum that covers all of the chambers. A needle may be inserted throughthe septum into any of the adjacent chambers of the receptacle.

In some variations, the fluid receptacle of the access port is dividedup into a plurality of fluid-locked chambers. As used herein, the term“fluid-locked” means that injection (or withdrawal) of fluid from one ofthe chambers does not substantially change the fluid within the otherchambers (although some fluid may be exchanged at the interface betweenthe chambers by diffusion or due to turbulence); instead, the majorityof fluid is exchanged between the chamber and the port stem, which maybe connected to a catheter implanted into a subject's vasculature. Asdescribed further below, the fluid-locked chambers are configured sothat as fluids are infused or aspirated from the system, only fluid inthe accessed chamber are exchanged, as differential fluid pressures arenot created to cause fluid to flow in the other chamber(s). Thus, thereis no substantial fluid flow between the chamber into which the fluid isapplied and the other chamber(s). In one embodiment, the plurality offluid-locked chambers may divide the fluid receptacle into approximatelyequivalent volumes.

In one embodiment, the fluid-locked chambers are formed by at least oneinsert. The insert may be one or more pieces of formed material (e.g.,metal, plastic, etc.) that is shaped to create barriers separating thereceptacle into multiple chambers when inserted into the fluidreceptacle of the access port. The insert may be a separate insert(e.g., formed separately form the rest of the housing) or it may beintegral to the housing of the access port (e.g., formed as part of therest of the housing). The insert may include an opening or gap to allowfluid to flow between each chamber of the fluid receptacle and the portstem. In some variations, the opening is oriented along the centerlineof the port stem. The insert may be any appropriate shape and may havean open “top” over which the septum fits so that a needle can access thechambers. For example, the insert may be configured as a round, linear,or pie-shaped insert.

In another embodiment, a fast clear port may include a base mat disposedwithin the fluid receptacle. In general, the base mat may be positionedon the base of the fluid receptacle and can reduce the fluid volumewithin the receptacle (or chambers of the receptacle in multi-chamberaccess ports), while allowing the needle (e.g., the sharp or beveled tipof the needle) to penetrate into the fluid mat so that opening into thelumen of the needle can be properly positioned within the receptacle.Thus, the tip of the needle may penetrate into the base mat (andeventually contact the bottom of the reservoir in the housing), allowingthe opening in the needle to access the fluid receptacle (or one of thechambers in a divided fluid receptacle). The base mat may be made of anyappropriate material that permits the penetration of a needle. Forexample, the base mat may comprise a silicone mat. Materials that arenot easily “cored” by a needle (e.g., elastomeric materials) may beparticularly useful.

In one embodiment, a multi-chamber implantable vascular access portincludes a housing having a divided fluid receptacle (that is dividedinto a plurality of chambers), a base mat disposed within the dividedfluid receptacle, a port stem in fluid connection with each chamber ofthe receptacle, and a septum configured to cover the chamber. The portstem is configured to couple to a catheter. In some variations, a covermay be included that has a window or opening exposing the septum. Thecover may attach to the housing.

In some variations, the fluid-contacting surfaces within the receptacleof an access port are hydrophobic. These fluid-contacting surfaces(e.g., the walls, floor, etc.) may be made of, layered, or coated with ahydrophobic material, including highly hydrophobic materials. Forexample, the fluid-contacting surfaces may comprisepolytetrafluoroethylene (PTFE). Hydrophobic (or lubricious) surfaces mayalso enhance fluid clearance from the access port.

In one embodiment, an implantable port includes a housing including afluid receptacle divided into two or more chambers, a port stem in fluidcommunication with the fluid receptacle, and a septum configured tocover the fluid receptacle such that the chambers are fluid-locked. Inanother embodiment, an implantable port includes a housing including afluid receptacle divided into a plurality of chambers, a base matdisposed within the fluid receptacle, a port stem in fluid communicationwith each of the chambers, and a septum configured to cover the fluidreceptacle.

Also described herein are methods of manufacturing an implantablevascular access port having a divided fluid receptacle. In oneembodiment; the method includes forming a plurality of chambers within afluid receptacle of the access port and covering the fluid receptaclewith a septum. As mentioned, in certain embodiments, a plurality ofchambers may be formed by placing an insert within the fluid receptacleof the access port so that the insert divides the fluid receptacle intodifferent chambers that are fluidly connected to a port stem of theaccess port. The insert may be attached within the receptacle (e.g., byan adhesive or snap-fit connection), held in place by the septum, orotherwise secured to create the multiple chambers within the fluidreceptacle of the access port. Also as mentioned, in certainembodiments, the method may include the step of inserting a base mat(e.g., a silicone base mat) into the fluid receptacle before placing theinsert. In addition, a fluid-contacting surface of at least one of thechambers of the access port may be coated with a hydrophobic coating. Insome variations, the step of coating a fluid-contacting surface of thefluid receptacle with a hydrophobic coating includes coating the wallsof all of the chambers within the fluid receptacle with a highlyhydrophobic coating, such as PTFE. In one embodiment, a method ofmanufacturing an implantable port includes forming a plurality ofchambers within a fluid receptacle by positioning an insert therein, theinsert being positioned such that each of the formed chambers is influid communication with a port stem, and covering the fluid receptaclewith a septum such that the chambers are fluid-locked.

These and other embodiments, features and advantages will become moreapparent to those skilled in the art when taken with reference to thefollowing more detailed description of the invention in conjunction withthe accompanying drawings that are first briefly described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of one example of a vascular access port.

FIG. 2 is a cross-sectional view of one embodiment of a fast clear port.

FIG. 3 is an enlarged view of a portion of the fast clear port of FIG.2.

FIG. 4 is an exploded view of another embodiment of a fast clear port.

FIG. 5 is a perspective cutaway view of another embodiment of a fastclear port.

FIG. 6 is a cross-sectional view of the fast clear port of FIG. 5.

FIGS. 7A to 7C show cross-sectional, side perspective, top, and sidecross-sectional views (respectively) of one embodiment of a fluidreceptacle region of a fast clear port.

FIG. 7D shows a cutaway perspective of an access port incorporating thefluid receptacle region shown in FIGS. 7A to 7C.

FIG. 8 is a side perspective view of a portion of another embodiment ofa fast clear port.

FIG. 9 is a side perspective view of another embodiment of a fast clearport.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings, in which like elements in different drawings are identicallynumbered. The drawings, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope of theinvention. The detailed description illustrates by way of example, notby way of limitation, the principles of the invention. This descriptionwill clearly enable one skilled in the art to make and use theinvention, and describes several embodiments, adaptations, variations,alternatives and uses of the invention, including what is presentlybelieved to be the best mode of carrying out the invention.

The fast clear ports described herein generally include a housing havinga fluid receptacle (also referred to as a fluid reservoir), a port stemin fluid connection with the fluid receptacle, and a septum covering thefluid receptacle. In certain embodiments, the fast clear ports mayinclude features that are believed to increase the clearance of fluidfrom the access port, including, for example, a base mat within thefluid receptacle, a multi-chambered configuration, a hydrophobic coatingover one or more surfaces of the fluid receptacle, and combinationsthereof.

FIG. 1 illustrates an exploded view of one example of a vascular accessport. In FIG. 1, the housing 101 holds a fluid receptacle 103 that isconnected to a port stem 105. Fluid within the fluid receptacle 103 canflow into or out of the port stem 105 through the connecting passage107. The port stem 105 and the housing 101 may be fabricated separatelyand joined, or they may be fabricated as a single piece (e.g., byinjection molding, casting, etc.). The port stem 105 may be configuredto couple to a catheter. For example, the port stem 105 may be elongatedand ridged or graded so that when it is inserted into the lumen of acatheter, the catheter will be secured on the port stem 105. Adisc-shaped septum 110 is shown above the housing, the septum 110 beingconfigured for placement over the fluid receptacle 103 such that aportion thereof rests on a shoulder 109 of the housing 101. The septum110 may be made of any appropriate needle penetrable material. A cap 120with window 121 that is open to allow a needle to access the septum 110(and therefore the fluid receptacle 103), is configured to attach to thehousing 101 and secure the septum 110 to the housing 101. The cap 120can also include openings configured to permit insertion of suture plugs122, 122′.

A cross-sectional view of a fast clear port having a base mat is shownin FIG. 2. This access port is similar to the access port shown in FIG.1 in certain aspects, but includes a base mat 201 disposed within thefluid receptacle of the housing 202, positioned on a bottom 205 of thefluid receptacle of the housing 202. The priming volume of the fluidreceptacle is reduced by the volume of the base mat 201. As describedabove, the priming volume is the volume of fluid contained within theport and port stem (and may include the fluid within an attachedcatheter). This is also typically the volume of fluid that must becleared to deliver fluid from a needle to the body site at the distalend of an attached catheter. The base mat may be made of any appropriatematerial, including a material that is hydrophobic and/or that may berepeatedly punctured by the tip of a needle inserted into the receptacleof the access port. For example, the base mat may include the samematerial as the septum. Examples of potential materials for the base matinclude silicone (polysiloxanes), elastomeric materials, andcombinations thereof.

The base mat may both reduce the priming volume of the access port, aswell as assist in positioning a needle 220 that has been inserted intothe access port, as shown in FIG. 2. The tip of the needle 220 maypenetrate the base mat 201, allowing the opening in the needle tip to bepositioned within the fluid-containing portion of the fluid receptacle230, so that fluid may be efficiently ejected or withdrawn from theneedle. Without a needle-penetrable base mat, the opening into theneedle lumen has the potential to be positioned a distance (e.g., 310,FIG. 3) above the bottom 205 of the fluid-containing portion of thefluid receptacle 230. The base mat 201 allows the opening in the needletip to be positioned closer to the bottom of the fluid-containingregion, thereby eliminating the need for excess volume within the fluidreceptacle, even when using standard (e.g., beveled) needles.

FIG. 3 shows a detail (from region A of FIG. 2), showing the needle 220interacting with the base mat 201. The distal tip of the needle 220 haspenetrated the base mat 201 until it contacts the bottom 205 of thefluid receptacle region of the housing 202. The housing 202 may be madeof a non-penetrable material, such as, for example, a plastic material(e.g., Delrin®). In FIG. 3, the opening 300 into the lumen of the needle220 is positioned with respect to the thickness of the base mat 201 sothat the opening is substantially within the fluid-containing region ofthe receptacle 230. The fluid-containing region is fluidly connected tothe port stem 208. In one embodiment, the thickness 310 of the base mat201 corresponds to the distance between the needle point and the opening300 of the needle 220 such that no portion of the opening 300 isobstructed. In another embodiment, the thickness 310 of the base mat maybe chosen so that only a small portion 302 of the opening 300 of theneedle 220 is obstructed by the base mat when the needle penetrates thebase mat. It should be appreciated, however, that any thickness of thebase mat with respect to the needle opening is contemplated herein aslong as some portion of the needle opening remains unobstructed uponinsertion into the fluid receptacle. A standard 19 or 22 gage needle maybe used to apply or withdraw fluids from the fast clear ports, althoughany appropriate needle may also be used.

The fluid contacting portion of the fluid receptacle of an access portmay have a hydrophobic surface which may enhance clearance of fluid fromwithin the fluid receptacle. Clearance may be enhanced when the fluidcontacting surfaces have less surface energy or affinity for injected(or withdrawn) materials. Thus, the fluid-contacting surfaces within thefluid receptacle may be lubricious (or low-friction) surfaces. Suchslippery surfaces are believed to greatly reduce the frictionalresistance to the passage of material. Hydrophobic surfaces may morerapidly and readily pass fluid. Hydrophobic, particularly highlyhydrophobic surfaces, are believed to have a tendency to repel waterbecause their adhesive energy and critical surface energy are very lowand their contact angle is very high (the contact angle refers to thewetting contact angle of water on the surface). The surface may behydrophobic because it is made from a hydrophobic material, or becauseit is coated or treated with a hydrophobic material.

Examples of appropriate hydrophobic materials that may be used includeany appropriate low-friction material, such as: fluoropolymers (e.g. FEP(Fluorinated Ethylene-Propylene), PFA (perfluoroalkoxy polymer resin),PTFE (polytetrafluoroethylene), etc.), silicones, paraffins,polyethylene, etc. Super hydrophobic materials are included ashydrophobic materials. For example, polytetrafluoroethylene (PTFE) isconsidered a “super hydrophobic” material, and can be pre-dispersed asan ingredient in a thermoplastic compound or used as a base component ina coating formulation in order to reduce the coefficient of friction.PTFE particles embedded in a thermoplastic compound or coating materialare believed to form a highly lubricious solid film over the surface.Any of the fluid-contacting surfaces within the access port (e.g.,surfaces contacting the applied or withdrawn fluid) may be made of,treated with, or coated with a hydrophobic material. For example,surfaces may be made hydrophobic by modifying them using a process suchas cold gas plasma, or by coating them with hydrophobic coatings.

Returning to FIG. 2, the access port shown includes a hydrophobiccoating 210 on one or more of the sides of the fluid receptacle, as wellas the walls of the port stem 208. In one embodiment, the port stem 208is made of titanium or molded plastic and is coated with a material suchas PTFE to provide advantages, such as, for example, improved clearancekinetics. Any of the fluid-contacting surfaces of the access port(particularly within the fluid receptacle region of the access port) mayinclude a hydrophobic surface. For example, the fluid receptacle regionmay be bounded by the walls of the inner portion of the housing, thebase of the inner portion of the housing, and the bottom of the septum,as shown in FIG. 1. Any (or all) of these surfaces may be hydrophobic.In addition, structures within the fluid receptacle (e.g., the walls ofany insert forming the multi-chamber access ports as described below)may be hydrophobic, as well as the inner portion of the port stem and/orcatheter.

In general, the access ports described herein may include any size orshape housing, fluid receptacle, and septum. Thus, although the fluidreceptacles illustrated in the figures are shown as cylindrical (e.g.,having a round cross-section), non-cylindrical shaped fluid receptacles(e.g., ovoid, rectangular, polygonal, etc.) may also be used. In somevariations, more than one fluid receptacle may be used. The fluidreceptacle may also be divided into chambers to increase priming volumeas described below.

In one embodiment, the fluid receptacle of an access port may be dividedinto a plurality of chambers to reduce the effective volume of the fluidreceptacle; the fluid receptacle may be subdivided into two or morechambers. In this embodiment each chamber has a path to a single lumenin a port stem (connecting to the catheter) so that fluid from thechambers is in fluid communication with a catheter or other conduitattached to the port stem. In certain embodiments, the multiple chambersare part of a single fluid receptacle. FIG. 4 shows an exploded view ofone variation of a multi-chamber implantable vascular access port (fastclear port). The fast clear port includes a housing 401 that has aninner region forming a fluid receptacle 405. A base mat 403 may beincluded within the fluid receptacle, and an insert 410 divides thefluid receptacle into three equivalent chambers. The insert may includeone or more opening to allow fluid to flow between the chambers of thereceptacle and the port stem (and thus the catheter). Aneedle-penetrable septum 415 fits over the insert 410 to cover theseparate chambers created in the fluid receptacle 405. Four suture plugs420 may also be included, as well as a cap 425 to secure the edge of theseptum 415 against the housing 401. A port stem 407 is shown connectedto the housing 401.

A multi-chamber access port may be manufactured by assembling the partsshown schematically in FIG. 4. For example, a method of manufacturing animplantable vascular access port having a divided fluid receptacle mayinclude forming a plurality of chambers within a fluid receptacle of theaccess port by placing an insert 410 within the fluid receptacle 405 ofthe access port so that the insert 410 divides the fluid receptacle intodifferent chambers that are fluidly connected to a port stem 407 of theaccess port. Although FIG. 4 shows a multi-chamber fast clear port thatincludes a base mat within the fluid receptacle of the access port,certain embodiments do not include a base mat 403. For example, in somevariations, the insert 410 is positioned directly against the base ofthe inner portion of the housing forming the fluid receptacle 405.Moreover, as explained above, any of the fluid-contacting surfaces ofthe chambers the fluid receptacle may be hydrophobic. In somevariations, the surfaces are coated with a hydrophobic material (e.g.,PTFE).

The multi-chamber access ports described herein may include two or morechambers, which may be configured in a variety of shapes and sizes.FIGS. 5 and 6 illustrate another variation of a multi-chamber accessport. In the cutaway view shown in FIG. 5, a fluid receptacle has beendivided into two chambers, an outer chamber and an inner chamber. Theouter chamber 604 of the fluid receptacle and the inner chamber 606 ofthe fluid receptacle are formed by a circular insert 610. When a needle220 is inserted through the septum 515 of the access port, it can entereither the inner chamber 606 or the outer chamber 604 of the fluidreceptacle, depending on where the needle is inserted through the septum515. In one embodiment, the inner chamber 606 and outer chamber 604 ofthe fluid receptacle hold a substantially equivalent volume of fluid.FIG. 6 shows a cross-section through the fluid receptacle of the accessport shown in FIG. 5. The insert 610 can be seen as circular, having anopening 620 positioned in fluid communication with the port stem 507.The opening 620 is a fluid exit (or entrance) site through which fluidflows from the inner chamber 606 into the port stem, passing through aregion of the outer chamber 604.

In general, the different chambers of the fluid receptacle may befluid-locked, meaning that when fluid is added or taken from onechamber, it does not substantially get taken (or added) from the otherchambers of the fluid receptacle. Fluid-locking may be a result of theconfiguration of the fluid pathways into and out of the differentchambers. For example, the inner and outer chambers 606, 604 shown inFIG. 6 are fluid locked because an increase or decrease in fluidpressure in one chamber does not result in a substantial fluiddifferential in the other channel, and thus there is not a substantialflow into or out of the other channel. Because the exit (or entrance)from the inner 606 chamber is aligned with the port stem pathway exitingthe access port into a large (possibly variable) volume, fluid insertedinto the inner chamber 606 will exit the access port withoutsubstantially entering the outer 604 chamber. Similarly, fluid insertedinto the outer 604 chamber will exit the access port withoutsubstantially entering the inner 606 chamber. In general, a vesselincluding a plurality of fluid-locked chambers will not have differentpressures in the other chamber(s) when the fluid pressure changes in onechamber. Although some fluid may be exchanged between the chambers(e.g., by diffusion or turbulence), the majority of fluid will beexchanged between the chamber into which the needle is inserted, theport stem and catheter or fluid conduit attached thereto. In FIG. 6, thedifferent chambers are connected by an opening 620 in the insert 610.This opening 620 is oriented on the centerline of the inner diameter ofthe port stem 625. As mentioned above, the different chambers may defineequivalent volumes or fluid pathways. For example, the insert shown inFIG. 6 divides the fluid receptacle into multiple chambers that holdapproximately the same amount of fluid. Thus, fluid injected into any ofthese chambers may clear at approximately the same rate.

In operation, a needle 220 is inserted through the septum 515 of amulti-chamber fast clear access port and a single chamber is accessedfor infusion of fluid. Since the barriers forming the separate chambersare relatively thin, it is believed to be unlikely that they willinterfere with the insertion of the needle. However, in some variations,the top of the barriers (e.g., inserts) may be rounded or beveled tohelp deflect the tip of the needle so that the needle inserts into onechamber or another. Further, the barriers (e.g., formed by an insert)may be made of a needle-impenetrable material. When the port andcatheter are primed with fluid (e.g., when any air is evacuated), needlewill inject or aspirate from the access port by exchanging the volume ofthe chamber in which the needle was inserted. Because the differentchambers are fluid-locked, the transport between chambers is minimizedand the majority of fluid is exchanged between the chamber into whichthe needle inserted and the larger volume represented by the opencatheter connection to the port stem. Because of the lack ofdifferential pressure, flow from (or into) other chambers (other thanthe one in which the needle is inserted) arises mostly from diffusionand small eddy currents.

The fluid receptacle may be divided into multiple chambers by anyappropriate structure, including the inserts described above (and shownin the figures), as well as by barriers that are formed integrally withthe housing. For example, the housing may be formed of a plasticmaterial that is molded, extruded, etc., and the barriers between thechambers are formed with the rest of the housing. In some variations, aninsert may be removable or formed separately and attached to thehousing. Furthermore, the insert(s) forming the different chambers maybe any appropriate shape, including rounded (e.g., oval, circular,etc.), or liner. An insert may be a single piece or multiple pieces. Forexample, the insert may be a thin flat strip of material that has beenbent or formed into a particular configuration or shape. A flat regionof the insert may form walls (barriers) between the different chambers.The insert may be secured within the fluid receptacle by any appropriatemeans. For example, the insert may be compressed between the base of theinner portion of the housing and the septum (particularly when anelastomeric base mat is used), or the insert may be attached within thefluid receptacle through the use of an adhesive, solvent, weld, and/orother attachment methods known to one skilled in the art.

FIGS. 7A-D show another variation of a region of the housing of amulti-chamber fast clear access port. FIG. 7A shows a section throughthe housing of an access port having a pie-shaped insert that dividesthe fluid receptacle 710 into three approximately equivalent,fluid-locked regions (v1, v2, v3). One side of the insert 701 is affixedto a wall of the inner region of the housing (e.g., by a silicone seal).The opposing side of the insert includes an opening so that fluid withinv2 may exit into or enter from the port stem when differential pressureis applied within a chamber. The insert 701 is positioned within thefluid receptacle such that sides 703 and 705 do not contact the walls ofthe fluid receptacle, permitting fluid to flow between v1 and the portstem and v3 and the port stem. A perspective view of this housing regionis shown in FIG. 7B. The walls of the insert 701 project up from a baseof the fluid receptacle 710, so that the bottom of the septum (notshown) can completely seal off the chamber formed by the insert when theseptum is attached to the housing region. In general, the chambers v1,v2, v3 may be sealed except for the opening fluidly connecting them withthe port stem and catheter or fluid conduit attached thereto. FIG. 7Cshows a top view of this same region of the housing. FIG. 7D shows aperspective cut-away view of a fast clear port 720 incorporating thehousing region and insert 710 described in FIGS. 7A-7C, in which theseptum has been removed to show the divided fluid receptacle region ofthe housing. In addition to the insert 701, fast clear port 720 includesa base mat 706.

FIG. 8 illustrates a dual-chamber fast clear port 810, showing a portionof a housing including insert 801 that divides a fluid receptacle intotwo approximately equivalent chambers. The insert 801 is positioned suchthat a fluid pathway is provided between each created chamber and theport stem (not shown).

In one embodiment, a fast clear port includes more than one fluidreceptacle (e.g., two, three, etc.), each fluid receptacle having two ormore chambers formed by an insert. As discussed above, the insert may beseparate from the fluid receptacle and secured therein duringmanufacturing, or the insert may be an integral portion of the fluidreceptacle (e.g., molded into the fluid receptacle). In one variation ofthis embodiment, a single port stem is connected to the multiple fluidreceptacles via separate passageways. Thus, for example, in anembodiment including two fluid receptacles, the port stem would bedivided along its length into two separate passageways, each of which isrespectively fluidly connected to a fluid receptacle with multiplechambers. One example of this embodiment is shown in FIG. 9, in whichfast clear port 910 includes a first fluid receptacle 902 and a secondfluid receptacle 904. A port stem 906 has a first passageway 912 fluidlyconnected to fluid receptacle 902 and a second passageway 914 connectedto fluid receptacle 904. Although not shown, in this embodiment a firstand second septum cover the first and second fluid receptaclesrespectively, extending through openings 922 and 924, and suture plugsare fashioned to be inserted within the cap openings 908. In such anembodiment, a dual lumen catheter (not shown) with separate lumens couldbe attached to the port stem such that the fluid contained within eachfluid receptacle remains separated throughout a length of the catheter.As stated, each fluid receptacle of a fast clear port with more than onefluid receptacle may contain two or more chambers formed by an insert.The multiple chambers of each fluid receptacle, in one embodiment, arein fluid communication with the same passageway of the port stem andrespective lumen of the catheter.

In another variation of this embodiment, each fluid receptacle isconnected to a different port stem, each of which is connected to aseparate single lumen catheter. As described above, each of the chambersof the fluid receptacles in a fast clear port including more than onefluid receptacle could be fluid-locked. Moreover, each of the fluidreceptacles, or individual chambers thereof, could contain one or morebase mat. Further, surfaces of one or more of the chambers could becoated with a hydrophobic material.

As mentioned, certain embodiments of the multi-chamber fast clear portsdescribed herein may be used in combination with one or more base mats.For example, an insert may be applied between a base mat and a septum.In some variations, multiple base mats may fit into each chamber.Furthermore, any of the fluid-contacting surfaces of the fluidreceptacle (e.g., the barriers or walls forming the separate chambers)may be hydrophobic. In some variations, all of the fluid contactingsurfaces within the fluid receptacle are hydrophobic. A vascular accesssystem may include any of the fast clear ports described herein (or anycombination of these ports). In addition, a vascular access system mayinclude a catheter configured to be implanted within a subject so thatthe distal end of the catheter is adjacent to a target site, and theproximal end of the catheter is configured to attach to the port stem ofa fast clear port. Systems may also include a needle or needles foraccessing the fast clear port. A fast clear port or system may also beincluded as part of a kit. Kits may include instructions (in any man ormachine-readable format), and may be packaged and/or sterilized formedical use.

As described above, a fast clear port may be implanted into anyappropriate region of subject, particularly a subject in need thereof.(As used herein “subject” may include any appropriate subject, includingnon-human subjects). A method of implanting the fast clear port includesimplanting a catheter so that the distal end of the catheter ispositioned adjacent to a target site after the port has been implanted,attaching the proximal end of the catheter to the port stem of an accessport, and implanting any variation of the fast clear ports describedherein. Once the fast clear port has been implanted, it may be used byinserting a needle (e.g., a 19 or 21 gauge needle) through the septumand into a fluid receptacle region of the access port. The needle may beinserted until the needle tip opening is positioned in thefluid-containing region of the housing. In some variations, this meansthat the tip of the needle penetrates the base mat until the tipcontacts the non-penetrable base of the housing. Fluid may then beinjected into (or withdrawn from) the fluid receptacle of the accessport. In some variations, the needle is inserted through the septum intoone of a plurality of component chambers that makeup the fluidreceptacle. After inserting or removing fluid, the needle can bewithdrawn. Thus, the access port can be used repeatedly.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an” and “the” include plural referents unlessthe context clearly dictates otherwise. Thus, for example, the term “aport” is intended to mean a single port or a combination of ports, “afluid” is intended to mean one or more fluids, or a mixture thereof. Inaddition, it is to be understood, that unless otherwise indicated, thisinvention need not be limited to applications in human. As one ofordinary skill in the art would appreciate, variations of the inventionmay be applied to other mammals as well. Moreover, it should beunderstood that embodiments of the present invention may be applied incombination with various catheters, drug pumps, and infusion devices.

This invention has been described and specific examples of the inventionhave been portrayed. While the invention has been described in terms ofparticular variations and illustrative figures, those of ordinary skillin the art will recognize that the invention is not limited to thevariations or figures described. In addition, where methods and stepsdescribed above indicate certain events occurring in certain order,those of ordinary skill in the art will recognize that the ordering ofcertain steps may be modified and that such modifications are inaccordance with the variations of the invention. Additionally, certainof the steps may be performed concurrently in a parallel process whenpossible, as well as performed sequentially as described above.Therefore, to the extent there are variations of the invention, whichare within the spirit of the disclosure or equivalent to the inventionsfound in the claims, it is the intent that this patent will cover thosevariations as well. Finally, all publications and patent applicationscited in this specification are herein incorporated by reference intheir entirety as if each individual publication or patent applicationwere specifically and individually put forth herein.

1. An implantable port, comprising: a housing including a fluid receptacle divided into two or more chambers; a port stem in fluid communication with the fluid receptacle; and a septum configured to cover the fluid receptacle such that the chambers are fluid-locked.
 2. The port according to claim 1, wherein the fluid receptacle comprises two chambers.
 3. The port according to claim 1, wherein the plurality of fluid-locked chambers divide the fluid receptacle into approximately equivalent volumes.
 4. The port according to claim 1, further comprising a second fluid receptacle divided into two or more chambers, wherein the port stem includes a first passageway in fluid communication with the fluid receptacle and a second passageway in fluid communication with the second fluid receptacle, and wherein a second septum is configured to cover the second fluid receptacle such that the chambers of the second fluid receptacle are fluid-locked.
 5. The port according to claim 1, further comprising a base mat disposed within the fluid receptacle.
 6. The port according to claim 5, wherein the base mat comprises a silicone material.
 7. The port according to claim 1, wherein fluid-contacting surfaces of the chambers comprise a hydrophobic material.
 8. The port according to claim 1, wherein the hydrophobic material comprises polytetrafluoroethylene.
 9. The port according to claim 1, wherein the fluid-locked chambers are formed by at least one insert.
 10. The port according to claim 9, wherein the insert comprises a pie-shaped insert, dividing the fluid receptacle into three chambers.
 11. An implantable port, comprising: a housing including a fluid receptacle divided into a plurality of chambers; a base mat disposed within the fluid receptacle; a port stem in fluid communication with each of the chambers; and a septum configured to cover the fluid receptacle.
 12. The port according to claim 11, wherein fluid-contacting surfaces of the chambers comprise a hydrophobic material.
 13. The port according to claim 12, wherein the hydrophobic material comprises polytetrafluoroethylene.
 14. The port according to claim 11, wherein the base mat comprises a penetrable material.
 15. The port according to claim 11, wherein the plurality of chambers are fluid-locked.
 16. The port according to claim 11, wherein the plurality of chambers are formed by an insert positioned within the fluid receptacle.
 17. A method of manufacturing an implantable port, comprising: forming a plurality of chambers within a fluid receptacle by positioning an insert therein, the insert being positioned such that each of the formed chambers is in fluid communication with a port stem; and covering the fluid receptacle with a septum such that the chambers are fluid-locked.
 18. The method according to claim 17, further comprising inserting a base mat within the fluid receptacle.
 19. The method according to claim 17, further comprising inserting a silicone base mat into the fluid receptacle before placing the insert into the fluid receptacle.
 20. The method according to claim 17, further comprising coating a fluid-contacting surface of at least one of the chambers of the access port with a hydrophobic coating.
 21. The method according to claim 20, wherein positioning comprises molding the insert into the fluid receptacle.
 22. An implantable port, comprising: means for dividing a fluid receptacle of the port into a plurality of chambers; means for preventing contact with a bottom of the fluid receptacle disposed within the fluid receptacle; a port stem in fluid communication with each of the chambers; and means for covering the fluid receptacle such that the chambers are fluid-locked. 